Prescription opiate drug misuse is strongly associated with alcohol dependence, and both conditions cause disproportionate harm to American Indian (Al) communities. Contingency management (CM) is a behavioral intervention designed to increase drug abstinence that has been associated with reduced opiate use in a number of studies. CM is understudied in the treatment of 1) alcohol use disorders; 2) polysubstance use disorders; and 3) Native populations. Previous studies of CM for alcohol dependence have used alcohol breath tests that are capable of detecting use for only 12 hours. Because breath tests cannot detect use between clinical assessments, their use leads to inconsistent delivery of interventions. We propose a study that will address this critical methodological barrier by using a CM paradigm based on a superior alcohol measure, ethyl glucuronide urine tests, which can detect alcohol use 2 or more days after it has occurred. The goal of this study is to perform a randomized, controlled trial to evaluate the ability of a culturally-tailored CM intervention to increase alcohol and opiate abstinence among Al tribal members from 2 reservations. Fort Peck in Montana and Quinault in Washington State. Treatment-seeking individuals with alcohol dependence and prescription opiate misuse will be randomized into to 1 of 4 groups that will recelive: (1) CM for alcohol, (2) CM for opiates. (3) CM for both substances, or (4) no CM for either substance. We aim to determine (1) whether participants randomized to CM conditions use less alcohol and opiates than those in the noncontingent (NC) control group, (2) whether the intervention is more effective for participants receiving CM for both alcohol and opiate abstinence, compared to participants in the single-substance CM groups or the NC control group. (3) group differences in secondary addiction-related outcomes and alcoholand opiate-associated health-Impairing behaviors. The proposed research Is innovative and has the potential to improve public health. By partnering with tribal communities to adapt, implement, and evaluate this trial, we will increase our tribal partners' knowledge of evidence-based addiction treatments and research, while improving their trust for addiction interventions in Al communities.